The differences between turbocharging and supercharging

Introduction and brief overview

Hello there, as many of you may have seen my last blogpost, DOHC v OHV v SOHC, I have now decided to make one about the differences between the two types of forced induction: Turbocharging and supercharging. Now due to my lack of researching ability (something I am slowly gaining knowledge of how to do), I will go over the basics of each and talk about some of their pros and cons. With that out of the way, let’s get on with it

Superchargers

Less common than turbos, the supercharger isn’t a bad thing. It’s actually quite a good thing. Although commonly found in cars with V8s that need more power cough cough Hellcat and Demon cough cough, the supercharger is now being put into cars such as the Toyota Yaris GRMN. Using two rotors (in both screw and roots type), the supercharger has a minor downside: It uses power to make power. Simply put, the because it is hooked up to the crankshaft, it uses some of the engine’s power to get going. However, once it is going, there’s really no stopping it. There is zero to little lag, and as a benefit, you get a very distinct whine from the engine bay

While turbos measure size in mm (the diameter of the turbine), superchargers measure in displacement (liters). For example: The Hellcat triplets (Charger, Challenger, and in this case, Grand Cherokee) all have a 2.4L supercharger which operates at 11.6 psi. However, to make that power, it is estimated that 80 HP is lost during the transaction.

Pros: Simple (compared with turbos), cheaper, sounds better (in my opinion)

Cons: Increased fuel consumption, using power to make power is counterproductive

Verdict: A great way to make a boat load of power with minimal compromise

Examples: 2003-2004 Ford SVT Mustang Cobra, Charger Hellcat, Jaguar F-Type (V6S, V8R, and SVR), Lotus Evora 400 (or just about any Lotus model), Toyota Yaris GRMN

Turbocharging

Just about every manufacturer uses a turbocharger in at least one of their cars in the lineup. The only one (that I’m aware of) that doesn’t use them is Toyota, Mazda, and Lotus? On the surface, a turbos workings are simple. There are two sides, an exhaust and an intake, as well as two turbines on each side. When the driver accelerates, exhaust gases go into the exhaust side and spin up the turbine. Because the intake and exhaust turbines are connected, the intake starts spinning as well, increasing air speed (correct me if that’s not the right term to use, I’m still pretty new to this stuff) which goes into the engine, to quote Jeremy Clarkson “Witchcraft happens and you go faster.” However, while the supercharger needs power to make more power, a turbo needs none of the sort. In fact, all it really needs are exhaust gases to get it spinning, then an air intake to keep the flow going. But what about when the pressure in the turbine gets too high? Well, that’s why the wastegate exists. The wastegate is there to release any excess pressure that would otherwise cause damage to the turbine and/or the engine.

While in cars with higher boost, a wastegate is almost a requirement, but in some cars, it won’t be necessary seeing as it doesn’t build enough pounds per squre inch (PSI) to break anything

One last thing, while a supercharger is measured in liters (of air it displaces), a turbocharger is measured in mm. Specifically, the diameter of the turbine itself. For example: a car that has a 72mm turbo will probably suck in small children while a 10mm turbo will not. But it isn’t all sunshine and rainbows however. Turbos have a problem with lag, or the time it takes for it to spool to full potential. Now car makers are finding ways around it with twin scroll turbos, sequential turbos and so on, but it lacks for that instant oomph that a supercharger does.

Pros: Can be just as powerful as superchargers while burning less fuel

Cons: Turbo’d motors don’t tend to sound as good, lag can be the make or break of an engine. Complex to implement

Verdict: A nice way to increase power and efficiency, but if you want nothing but power, then go for the supercharger.

What I would pick

Both are great ways to boost an engines output. While each have their drawbacks, in the end, I would have the supercharger mostly because of the lag-free effect, and the fact it sounds better. Let me know what you would have in the comments below and let me know if you have any suggestions too, I would love to here them. Until next time, goodbye!